There is heaps of meanings for 'whacked'.
a. To be killed.
b. To be hit.
c. Hungover.
d. Stupid.
e. Bloody awesome.
f. Drunk.
g. Stoned.
h. Not working properly.
i. Stuffed.

a. Man his car flipped straight off the cliff, police found him whacked.
b. he was so whacked, face was all bleeding and shit.
c. Ohh man I woke up so festy, my heads whacked.
d. What a fucking whacked driver, ran the red light straight in front of me.
e. You are so bloody whacked man, gotta love ya !
f. I've had so much yo drink me and Maddy are whacked as.
g. Fuck mannn I'm too whacked to talk all your serious shit.
h. Computers bloody whacked, heap of junk.
i. Good luck with that, I wouldn't bother with something so whacked !